Five open reading frames upstream of the dnaK gene of E. coli.

The nucleotide sequence of 3.17 kb of DNA upstream of the dnaK gene of E. coli was determined. Analysis of the sequence indicated the presence of five open reading frames (ORFs), two of which are coded on one strand and three on the other. ORFs 3 and 4 appear to constitute an operon. One of the ORFs (htgA) is preceded by a -10 promoter sequence which is identical to that of the dnaK sigma 32 P1 promoter, and thus suggests that htgA could be a heat-shock gene. ORF4 and htgA overlap each other on opposite strands of DNA, this would offer some interesting regulatory possibilities.